---
title: "Quote a machine/MPP fax without side effects"
method: POST
path: "/api/v1/machine/faxes/validate"
tags: ["machine"]
---

# Quote a machine/MPP fax without side effects

`POST /api/v1/machine/faxes/validate`

## Request

- Base URL: `https://singlefax.com`
- URL: `https://singlefax.com/api/v1/machine/faxes/validate`
- Auth: none required

## Request body

- object
  - `to` string, required: Destination fax number in E.164
  - `base64` string, required: Original document encoded as base64 (PDF, Office, text, or image). Do not convert to PDF first. We convert before sending.
  - `request_id` string, required: Client idempotency key for challenge + charge

## Response `200`

Quote

- MachineFaxQuote
  - `request_id` string, required
  - `amountCents` integer, required
  - `currency` string, required
  - `billablePages` integer
  - `destinationCountry` string
  - `protocol` string
  - `methods` string[]

## Other responses

- `503`: Service unavailable

---

[API](https://skmtc.dev/singlefax/apis/singlefax-api.md) · [All operations](https://skmtc.dev/singlefax/apis/singlefax-api/llms.txt) · [OpenAPI document](https://skmtc.dev/singlefax/apis/singlefax-api/revisions/f6fdbfac1e25?raw)